A company that plans to develop the former Lafarge quarry site says a west end proposal that includes a Costco could make its own development redundant.

“Our client is concerned that the large-format uses proposed by Armel would potentially duplicate the planned function of the Silvercreek mixed-use node,” says a letter filed at city hall Tuesday by lawyer Steven Zakem.

Zakem, who represents Silvercreek Guelph Developments Ltd., also questioned Armel Corp.’s request that the floor area of the proposed commercial development on the city’s western border not be capped. This request “requires careful review and balancing with the needs of the commercial policy for the city as a whole,” his letter says.

Armel’s proposal for a commercial development anchored by Costco, on land just west of the Zehrs on Paisley Road, went before city council for the first time Tuesday evening.

There used to be talk of a Costco going onto the Silvercreek site, but the huge warehouse membership retailer has chosen the Armel site instead.

Now Silvercreek Developments wants council to approve a change to allow a supermarket on its site. Ward 3 councillor June Hofland is opposed to this change, saying it would have an adverse impact on the neighbourhood in terms of increased traffic.

Zakem is asking council to evaluate Armel’s development application “in the context of, and contemporaneously with, the Silvercreek applications” for changes to the plan for development of the quarry site, which has been vacant since 1994.

Silvercreek is seeking changes to a December 2008 settlement with the city mediated by the Ontario Municipal Board. As well as allowing a supermarket,

Silvercreek is asking for a broader range of uses to be allowed for a 145,000-sq.-ft. big box store on its site, as well as removal of timing restrictions on its retail development on the former quarry site.

“It is critical,” Zakem’s letter says, “that the city’s commercial areas be planned comprehensively and consistently, as well as that optimal use be made of the unique location of the Silvercreek lands which enables them to serve both a local and a regional function.”

Armel’s proposed development on about 32 acres west of Elmira Road and north of Paisley Road would see the Costco built at the north end of the site as the first phase of a big development on the site, council was told Tuesday.

Tuesday’s meeting was a chance for the public to express its views on the proposed development before city planning staff make recommendations. There were no public delegations at the meeting. The only public comment came in a letter from Kyle Mackie, who urged council not to allow the Costco-anchored development.

“These developments result in trivialization, homogenization and dissipation of the independence and quality of places,” he wrote.

The Costco on Armel’s site could be as large as 158,000 square feet, Armel planning consultant Wendy Nott told council Tuesday.

She said the original plan called for the Costco to go in the middle of the site, but now there’s a new plan that’s more in keeping with city hall’s urban design goals.

It calls for a “pedestrian main street” at the south end of the site, where most of the development’s buildings would eventually go.

Nott said the proposed mixed-use development would eventually include high-density residential housing.

Jeff Ishida, Costco’s vice-president of real estate, said the warehouse membership retailer already has about 16,000 members from the Guelph area, including 4,000 business owners. These people currently go to Costco stores in other cities.

He said Costco hopes to have a zoning change and a site plan approved by this fall, so the new Costco can open in the fall of 2013.

The proposed development, which is across Elmira Road from the West Hills commercial development anchored by the city’s biggest Zehrs, includes land formerly occupied by the farmhouse of the pioneer Mitchell family. In a highly controversial 2005 decision, city council allowed Armel to demolish the two-story stone Mitchell farmhouse and grade the land.

As directed by council at that time, Armel will erect a monument to the Mitchell farmhouse somewhere on the site.

“I’ve heard it described as a cairn,” Nott said of the monument. She told council it will go at a “strategic location” on the site, but the spot hasn’t yet been determined.